This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Preliminary studies in rhesus macaques (RM) reveal that RM experimentally infected with the simian immunodeficiency virus (SIV) and rhesus rhadinovirus (RRV), the homologue of Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus 8 (HHV-8), develop B cell hyperplasia compared to RM infected with SIV alone. RRV, like KSHV, encodes an interleukin-6 (IL-6) homologue. The KSHV IL-6 homologue is thought to be a necessary growth factor for Kaposi's sarcoma and the B cell-derived malignancy referred to as body cavity-based lymphomas or primary effusion lymphoma in AIDS patients also infected with KSHV. The long-term objectives of this study aim to evaluate the role of the RRV IL-6 homologue in viral-mediated B cell hyperplasia in the context of an SIV infection. The results from these studies should help elucidate the role of the vIL-6 in virus infection and provide new insights into the future development of diagnostics and therapies for gamma-2 herpesvirus-induced malignancies.